Lucky South Yorkshire folk Olesia Tartakovski, of Sheffield and Rotherham's Mark Carew already know what it's like to win. They have each scooped the £1,000 first prize using Tengi. Read about Olesia's win - click here.

Thousands of others have won and are already enjoying the free chat app benefits of Tengi, which can also be used to set up group messaging.

Now bosses are planning to take it to the next level and take on the big boys.

The chat app that gives back, as they like to keep reminding people, is about to be promoted heavily, everywhere, in print, online, radio and TV.

After it conquers the UK...tomorrow the world.

Tengi aims to go global and it could become the next household name, on the lips of millions of smartphone chat app users everywhere. In Sheffield it could result in dozens of new jobs. At least that's the plan.

Blunt talking Yorkshireman Neil Laycock is certainly the right man for the job.

The CEO helped to launch Sheffield based internet service provider Plusnet with just a handful of staff and it has gone on to employ over 1,000 people.

He is now hoping to make a success story of Tengi, which has started life in the University of Sheffield's Bio-incubator, a new business start-ups building, in Leavygreave Road.

App experts from all over the world have been working on aspects of it but the steel city, now a thriving digital innovations centre, is very much its birthplace and home.

Tengi, free to download and use, offers all the usual messenger app function to send texts, emoticons, photos, videos and audio messages. It tells users when their message has been delivered and read.

It's easy to set up group chats with friends, family and anyone with shared interests, like a club or organisation.

The app can be also used by anyone with a mobile phone and a SIM card, with messages sent via the internet, including WiFi.

But what makes it special, unlike any other chat app, is the free weekly draw on Fridays at 7pm, explained Neil, who also managed online health site patient.co.uk.

The more you chat, or when your phone contacts sign up, the more virtual tickets you get that week, so the more chances of winning.

Users get eight tickets when a contact downloads Tengi, two if a friend wins, a ticket for each day they use the app, another for each time they spend 15 minutes chatting on it and there's even a ticket to be had each week just for keeping the app installed on your mobile.

To qualify for the £1,000 and £25 prizes you must also have at least one friend on Tengi.

Neil said: "There are lots of other messaging apps out there but we are different because of the free weekly prize draw. We will give away half of our revenues - forever. That is a really significant. Nobody has done that before.

"We earn this revenue from adverts in the app and we have given away around £100,000 in just our first 20 weeks of prize draws.

"I was approached with the concept of Tengi about 18 months ago. Since then we have opened the office, got staff there and utilised experts all over the world. But fundamentally the concept was created here in Sheffield. We are really proud of that.

"When I worked at Plusnet we started with only a few of us but now Plusnet employs over 1,000 people. At Tengi we are on much the same trajectory, with a big idea.

"I'd like to think we will grow with more people here and follow the same story as Plusnet, to make Tengi a global brand.

He promised: "We don't sell personal data and we don't give it to advertisers. We don't use message content to help target adverts and we don't charge users for anything - there are no in-app purchases.

"When anyone sees an ad within the app, we generate revenue and we give at least 50 per cent of that money back to our users. So as more people use Tengi, the more money we have to give away and who knows how big the prize pot will grow? One day it could £10,000 or even millions!

"Over the next couple of months we want people to help us spread the word far and wide.

"In a survey last year users let us know it was difficult to get friends and family to switch their chat to Tengi because there was a lack of awareness, and therefore trust in the app.

"To help overcome this we are building awareness through a number of campaigns, both nationally and regionally.

"As an alternative to claiming a cash prize via bank transfer, or as an amazon.co.uk gift code, winners can donate their prize to one of our partner charities. We're kicking this off with the Heart of England Forest, where every £5 prize donated will result in the planting of a new broadleaf tree.

"So there has never been a better time to download it and get your friends to do the same. We want users to invite as many people as they can and give us feedback."

The Star, supporting made in Sheffield businesses, is making it easy for readers to download Tengi. Whether you are an Apple or Android mobile user, to get the app from the Apple Store or Google Play, on your mobile simply visit tengi.com/star* Tengi is currently only available to UK residents over 16 years. As with other chat apps, sending messages and media when not on WiFi will use your data allowance.